In a flip-chip mounting method or multi-chip mounting method which has become more and more popular in recent years, sealing of the IC chip, after it has been mounted on a circuit board, according to a conventional method, was performed generally as shown in FIG. 3.
In FIG. 3, a circuit board 3, on which an IC chip 2 is mounted, is fixedly set by suction force on a block 1 which is heated to a prescribed temperature, for example 60.degree. C., and inclined at a predetermined angle .theta., for example 15.degree.. A sealing material (epoxy phenol resin) 5 is applied onto an upper surface 2a of the IC chip 2 by a dispenser 4 so as to let the sealing material 5 to run into between the IC chip 2 and the circuit board 3 by the 15.degree. inclination of the block 1, thereby accomplishing the sealing of the IC chip 2.
FIG. 4 shows the positional relationship between an application nozzle 4a of the dispenser 4 and the circuit board 3. As shown, the application nozzle 4a is positioned at a location where there is a gap h of, for example 0.2 mm, between the circuit board 3 and itself, before discharging the sealing material 5.
However, with the conventional sealing method as described above, when the discharge of the sealing material is started under such a condition that said gap h between the application nozzle 4a and the circuit board 3 is wider due to variation in dimensions such as thickness of the block 1 or the circuit board 3, the sealing material 5 is discharged on the IC chip 2 as shown in FIG. 5, which causes imperfect sealing.
In view of the problem in the prior art as described above, it is an object of the present invention to provide a method and device for sealing an IC chip by which the occurrence of imperfect sealing can be eliminated by surely feeding a sealing material onto the upper surface of a circuit board.